1. Field of the Invention
This invention pertains broadly to the field of fasteners and in particular to fasteners designed to retain a helical spring.
2. Description of the Related Art
Prior methods of retaining a helical spring have included placing one end of the spring over a fixed cylinder and then retaining the spring on the cylinder by way of clamps, two-piece collars, screws, brazing/welding or one or more pins placed through coils of the spring and the accompanying cylinder. Another technique includes using a tapered cylinder or mandrel upon which an end of the spring is pressed with the compression of the spring on the mandrel retaining the spring in place.
Of course, the need to fasten helical springs is varied. In one military application, a need arises where it is desired to affix a spring-based antenna onto a vehicle or other surface. Many military vehicles such as Jeeps, HUMVEEs, tanks, river patrol boats and the like oftentimes incorporate such antennas for communication purposes. The need extends not only to surface vehicles but to submersibles such as manned submarines and underwater robotic vessels. In the latter application, such a fastener should be able to hold a helical spring both when vibrated and when subjected to air and water flow. It is also desirable that a spring fastener be easy to manufacture, easy to implement and low in cost.